In storage subsystems, redundancy can be provided to protect data stored in such storage subsystems. One type of redundancy is mirroring redundancy, in which data in one storage device of the storage subsystem is copied to a mirror storage device (which contains a mirror copy of the data). Another type of redundancy is parity-based redundancy, where data is stored across a group of storage devices, and parity information associated with the data is stored in another storage device. If data within any storage device in the group of storage devices were to become inaccessible (due to data error or storage device fault or failure), the parity information can be accessed to reconstruct the data. Redundancy protection can be according to one of various RAID (Redundant Array of Inexpensive Disks) schemes, such as the RAID-1 scheme to provide mirroring, or the RAID-5 or RAID-6 scheme to provide parity-based redundancy.
In some cases, conventional mechanisms of providing redundancy protection for data stored in storage subsystems may be inefficient.